Carl eumpff



UNITED STATES PATENT OF ICE.

CARL RUMPFF, on APRATH, NEAR ELBERFELD, GERMANY.

MANUFACTURE OF BROWN DYE-STUFF.

SPECIFICATION forming part of Letters Patent No. 261,767, dated July 25,1882.

Application filed May 16, 1882. (Specimens) To all, whom it may concernBe it known that I, CARL RUMPFF, residing at Aprath, near Elberfeld, inthe Kingdom of Prussia and Empire of Germany, have invented a. new anduseful Improvement in the Mannfacture of Dye-Stuff or Coloring-Matter,of which the following is a specification. V

This invention relates to a brown dye-stuff or coloring-matter which isproduced by the action of diazoazotoluolsulphonate of soda uponnaphthylamine in acid solution.

In carrying out my invention 1 take fifty pounds ofamidoazotoluolsulphonate of soda dissolved in five hundred pounds ofwater cooled down to 3 centi grade. To this solution I add slowlyseventy-five pounds of lnuriatic acid, and thereafter eleven pounds ofsodium nitrite dissolved in forty pounds of water. Atter several hoursrest the liquid is poured into a solution containing twenty-five poundsof naphthylamine, fifty pounds of innriatic acid, and five hundredpounds of water. The new brown dye-stuff separates instantly as a voluminous precipitate, which is filtered and dried.

My dye-stuff, when dry, appears as a darkbrown powder. It is soluble inhot water, and

its aqueous solution takes a brown color by the addition of alkaline.Murintic acid or sulphuric acid dyes the aqueous solution bluish red.Itdyes wool and silk in a dark reddishbrown color in an acidulated bath,and this color is fast against soap and light.

W hat I claim as new, and desire to secure by Letters Patent, ism l. Theproduct described, consisting of a new brown dye-stuff orcoloring-matter which is produced by the action ofdiazmzotoluolsulphonate of soda upon lmphthylamine in acid solution. 1

2. The mode of preparing the within-described dyestutt', the sameconsisting in adding to a solution of amidoazotoluolsulphonate of soda,first, muriatio acid, then a solution of sodium nitrite, and then anacid solution of naphthylnmine, substantially as set forth.

CARL RUMPFF.

Witnesses ANTHONY GREF, J r., WM. A. PQLLOCK.

